ImageMeasure does not apply aspect_ratio to max width/height

[UkoeHB]

Bevy version

v0.16.1

What you did

Created a box and put an image as a child of the box. A node structure like:

"root"
     Node{width:100px height:100px}

     "img"
          Node{width:100% max_height:100%}
          ImageNode{image:"my_image.png", image_mode: NodeImageMode::Auto}

What went wrong

If my_image is too tall, then the image will compress vertically to respect max_height, without the width changing at all.

As ImageMeasure is currently designed, it is impossible to maintain an image's aspect ratio while getting it to fill a box of arbitrary dimensions.

Expected fix

ImageMeasure should follow these steps:

1. Maintain aspect ratio when applying max_height/max_width.
2. Maintain aspect ratio when applying min_height/min_width.
3. Clamp to min/max height/width. This is allowed to stretch the image.

Note that the following code currently exists:

let width = width.or(s_width
            .or(s_min_width)
            .maybe_clamp(s_min_width, s_max_width));

But IMO the .or(s_min_width) should be removed since it will interfere with applying aspect ratio when a min is hit.

[UkoeHB]

Not sure if this is ok in 0.16.2 milestone. Fixing it may break some UI that try to fudge around the problem.

[UkoeHB]

Related: DioxusLabs/taffy#804